I'm about to begin reloading some 6.5 Swede brass for a Ruger No 1.  I currently have both some Remington & Hornady brass and will most likely pick up some Norma brass sometime soon.  I've noticed that most reloading manuals test their loads with various brands of brass, primers, etc.   

My question is should I be concerned about mixing the brands of brass when reloading?  Any advice is greatly appreciated.

For safety, I develop loads in the cases with the smallest capacity. Once I'm pleased with the load, I try the same load in the larger capacity cases. If the latter group print differently from the former, I may tweak the amount of powder a little. Note that the pressure signs will be different from one brand of brass to the next, so you won't know whether to use more powder or less. You may not be able to make every brand print safely to the same point. Be very careful to watch for pressure signs when doing this.

I've found few issues when switching between commercial brass. I try to use one brand of brass with a single load while developing a load and keep with that combination of components. If I have to switch brass makes, or any other component for that fact, I drop back 10% on the powder charge and start over. Developing load with mixed brass is a habit best avoided as it introduces unnecessary variables.

Now mixing military and commercial is another thing. Military brass is usually thicker walls and can be quite hard.

Ed

I would second the vote for Lapua. I shoot 6ppc lapua, 6xc made from Lapua. Have found that the wall thickness, temper,  weight are the most consistant of all the brass i have used in any of my bench guns
  Larry